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MG Midget and Sprite Technical - Rear shackle

Another one from me please.....Poly pads and bushes now fitted. Pig of a job lining up the U bolt holes, but finally in back in place and all nuts reasonably tight until final tightening of everything once on the ground....I trust?

However, I note the nearside shackle is somewhat off the vertical - outboard direction. Not much, but definitely noticable. Offside is fine. It looks to me as if the shackle mounting plate - the trunnion that fits onto the boot floor looks skew slightly, which leads me to believe the reinforcement plate/area to which it mates to in the boo and fixed with the 3 fine thread bolts, is not square - or at least deformed slightly.

Does this matter? If so, what can be done?
Oggers

Depends on how much... I'd think (guess) anything beyond 3/8" would be an issue...i wonder what got hit under the car

Is it pushing the axle back or pulling the axle forward on that side? And by how much

Possible issues I'm guessing would be worn tire, wheel bearings, U JOINTS wearing, brake adjustment issues wear inside the pumpkin and suspension alignment to name a few

Was this the side that the wheel arch is dragging on the tire?

Prop
1 Paper

Photos may assist


Bad one as attached. Note the rear spring eye is not perpendicular to the shackle side plates.


Oggers

Good-ish one on the other side for comparison.


Oggers

I don't know really but if I put my tuppence's worth it might encourage better replies.

Is it the shackle or could it be the spring eye out of wack or perhaps even the floor at that mount or mount.

As nothing lines up on your average Spridget like on modern cars that might be compensated for by another variance(s) elsewhere or even perhaps compounded by another variance(s) or not matter overall anyway.

Those are certainly purple bushes wonder if they're the same as the FL/AVO ones.



Nigel Atkins

Nigel

It is the shackle plates which are not vertical - for some reason. The spring/eye sits in the correct horizontal plane. I have not dropped the thing on the wheels and bounced it around yet. That may assist matters, but in the meanwhile I am wondering what may be done
Oggers

Oggers,
When the car is back on the ground those plates wont be vertical anyway. The plates take up a near horizontal alignment (maybe a 30 degree angle) So it may not matter anyway. Or at least it may be far less apparent.

When you lower the car and the spring begins to take the weight, do be sure that the shackle rotates rearwards as they can have a tendancy to swivel forwards and upwards in which case the spring locks up in front of the upper rear shackle pivot. You may need to use a pry bar to encourage the shackle to turn the correct way as you lower the car. Once done, it will stay in its correct allignment even if you jack the car up again.
GuyW

Guy

I am perhaps not expressing myself well. What concerns me is the apparent mis-alignment of the spring eye and the shackle plate pivot - which when looking at the car from the rear means the shackle plates are skewed, or not at 90 degrees to the spring eye and pivot.

I agree that when down on the ground it may sort itslef out, or indeed when the shackle rotates it may not matter too much, but I would have though that as the spring eye moves straight upwards when absorbing bumps etc, then a sqaure parallelogram formed between eye, plates and the trunnion fixed to the boot floor would be required.

Then again, maybe I am worrying too much....

Oggers

You'll know more once the car has settled, you might be worrying too much as you say.

You could do a BL garage repair and place washers as required, repair washers at that. :)
Nigel Atkins

Yes Oggers, I could see what you were getting at. I just meant that in terms of spring alignment relative to the car body, it would be less out of line when it was sitting down on its wheels.

When you dismantled it, were the two pins parallel and at 90 degs to the fixed plate? Its difficult to tell as it could be a shadow effect in the photo but it looks as if the captive shackle plate is bent slightly, splaying the pins. You could dismantle it and straigten it which would then bring the pins parallel. But the boot floor also looks buckled up at one side so the floor would need beating down again with a FBH to bring it square to the spring eye. I don' know if it matters, though as it is the new bushes may wear prematurely.

I suspect the back end of the car has had a bit of a sideways impact at some time. Not necessarily on the bodywork - it could be nothing more than a bit of sideways drift into a kerb! Maybe time to check the wheel isn't buckled ?
GuyW

Did you notice if the end of the spring was trying to splay outwards when you refitted the shackle? I'm wondering if there is something slightly out of kilter either at the axle pads or the front mountings causing this? Did you notice if the shackle had the lean without the spring fitted?

Jim
J Smith

It's not really to obvious like guy said, it looks like something minor like hanging into a kerb or curb

It does look like there is a buckle in the floor

If it were me, I'd photo it all make some notes then assemble it all and then see what it does, its appears so minor and these cars have so much slop built in to the car it may not be a problem or even noticeable

Ive learned there is no such thing as perfection in these cars thus there individuality and charm

If there is a problem after assembled then deal with it, but it's so minor I'd risk having a good night's sleep without a 2nd thought

But that's me...im sure others will call me a flaw, I'm just saying that's what I'd do with this senerio

Prop

1 Paper

Having looked again at the first photo, are you sure that the shackle plate lower hole has located over the shoulder of the bolt correctly? The two plates don't look parallel.

Thinking back to when I did mine, I had this problem and had to 'persuade' the plate to fit over the shouldered bolts.

You can just see the shoulders here:
http://mgbhive.co.uk/product/midget/9-midget-rear-shackle-aha7686/


Jim
J Smith

I was thinking the same as Jim. I also wonder if the spring is twisted a bit, one of mine is and it’s a pig to get the shackle back together.
John Payne

<<are you sure that the shackle plate lower hole has located over the shoulder of the bolt correctly>>
Well spotted, Jim!

That could be aggravated if the fixed link is bent, as I said it appears to be, as this then causes the bolts to splay slightly and may not then locate correctly into the second link plate.
GuyW

There seems to be more thread through on the centre (inner) fixing.

Oggers,
a pre/selected-focus would help with detail on the photos.
Nigel Atkins

Chaps

The nuts are not fully tight - to be fully tightened when lowered. I take the points made, but would still comment that the shackle plate base does not sit in the same horizontal plane as the spring eye -as it surely should be, and also seems offset from the spring eye - as it surely should not be! The bushes seem to be taking up the distortion - which I don't like.

I think the spring sits pretty well, and although fully tightenting the plates may reduce the opffset a little, the line made by the top of the spring eye and the line made by the base plate edge would still not be parallel - as it ought to be.

Personally I think the boot mounting is wonky, and I am not too sure how to fix that - if it is at all required or indeed fix-able!. I will lower it sometime and see for sure.

Many thanks for the comments.

Oggers

>>>>the line made by the top of the spring eye and the line made by the base plate edge would still not be parallel - as it ought to be.<<<

I think you will find that things will improve a lot if the plate is located on the bolt shoulders correctly and the nuts tightened further. The lower mounting (the spring eye) in your photo appears a lot wider than the top one - which means that the poly bushes are not compressed/seated fully - so the spring eye could well be allowed to twist out of line.

Jim
J Smith

Another thought on this Oggers. You said you had difficulty fitting the U bolts at the axle seating. Although the spring fits positively at the pad with its locating peg, the U-bolts also locate positively in steel plates over the top of the axle where l think there are actually slight depressions to receive them. If the U bolts missed their locating groves they would splay slightly and be difficult to fit - as yours were. And the spring would also be forced laterally out of alignment at the rear.

As well as this, although final tightening needs to be done with the wheels on the ground, this is only the last half turn or so. You can tighten them up a good deal more than you have to align the shackle plates.
GuyW

That boot floor distortion could be corrected with a block of wood and a FBH !
GuyW

Guy

That's where my thoughts are also..

Might even be able to use a bottle Jack to take out distkdistortion of the floor
1 Paper

Jim

Yes - I see what you are driving at. I'll try tightening up and ensure shoulder location.

Guy

My problems were on the other side!....but point taken regarding tightening. U bolts locate over the saddle then either side of the mounting plate on the axle then through the holes of the mounting plates. Difficult to mis-align them I would have thought, though I accept the pads may become misaligned if they miss the locating hole in the mounting plate - which they don't appear to have done on mine.

I'll drop it off the stands, bounce it around a bit, tighten up, then revert.

Many thanks
Oggers

This thread was discussed between 14/11/2017 and 18/11/2017

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